The Rongzhai suibi 容齋隨筆 "Spontaneous essays of the Studio of Forbearance" is a collection of essays written by the Southern Song period 南宋 (1127-1279) scholar Hong Mai 洪邁 (1123－1202), courtesy name Hong Jinglu 洪景盧, studio name Rongzhai 容齋 or Yechu 野處. He came from Raozhou 饒州 (modern Boyang 波陽, Jiangxi) and was a son of Hong Hao 洪皓, a famous minister at the Song court. Hong Mai became official at the Historiography Institute (guoshiyuan 國史院) and member of the Hanlin Academy 翰林院. These positions allowed him access to the vast treasury of the imperial libaries with its fund of literature of all kinds. Hong Mai, although being a historiographer, was very fond of inofficial stories, collected a lot of them and published them in his books Yechu leigao 野處類稿, Yijianzhi 夷堅志 and Wanshou Tangren jueju 萬首唐人絕句 (a collection of poems).
The Rongzhai suibi is, similar to the Yijianzhi, composed of stories and informations that Hong Mai gathered during conversations and on the base of his vast lecture. It is 74 juan "scrolls" long and consists of five collections (ji 集), the Rongzhai suibi, Rongzhai xubi 容齋續筆, Rongzhai sanbi 容齋三筆, Rongzhai sibi 容齋四筆 and Rongzhai wubi 容齋五筆, each with a length of 16 juan, except the last collection that has only 10 juan because Hong Mai died before its completion. The essays included in the collections cover a very wide range of themes, from history, philosophy, literature, arts, and geography, to customs and habits. The book includes in total 1,230 small chapters, each dealing with a different theme. His book is especially noteworthy because of the citation of a lot of political matters from Song period laws, statutes and regulations, and information about Song period personalities. Hong Mai also commented some passages of ancient writings, like the Confucian ClassicsYijing 易經 and Shijing 詩經, and rectified errors in earlier Song period writings like Shen Kua's 沈括 collection Mengqi bitan 夢溪筆談 or the collection Dunzhai xianlan 遁齋閑覽 by Chen Zhengmin 陳正敏. In spite of all his accurateness and exact research, there are still some errors to be found in his book. The Rongzhai suibi is such a rich source of knowledge about the Song period that it was always used by traditional scholars side by side with the Mengqi bitan and Wang Yinglin's 王應麟 Kunxue jiwen 困學紀聞.
The first collection was printed in Wuzhou 婺州 shortly after its completion and was read by Emperor Xiaozong 宋孝宗 (r. 1162-1189) who recommended it. Hong Mai was therefore compelled to write continuations to it, which became the further collections Xubi, Sanbi etc. All five collections were printed by Hong Mai's grandson Hong Ji 洪汲 in 1212 in the Zhanggongjun Studio 章貢郡齋, with a preface written by He Yi 何異. Further prints were arranged by Ma Xunfu 馬巽甫, a friend of the family Hong, by Li Han 李瀚 during the Hongzhi reign 弘治 (1488-1505) of the Ming 明 (1368-1644), by Ma Yuandiao 馬元調 during the very late Ming period, in 1700, and during the Tongzhi reign 同治 (1862-1874) of the Qing 清 (1644-1911), a print that was reproduced as a faksimile in 1875.
The Rongzhai suibi is included in the collectaneaJindai mishu 津逮秘書, Siku quanshu 四庫全書, Sibu congkan 四部叢刊, Guoxue jiben congshu 國學基本叢書, Biji xiaoshuo daguan 筆記小說大觀, the Shangwu yinshuguan Press 商務印書館 edition of the Shuofu 說郛, and the collection Jiu xiaoshuo 舊小說, but only in an abridged form. A modern edition was published in 1978 by the Shanghai guji press 上海古籍出版社 on the base of the 1875 faksimile edition.